Metabolic Control Analysis of Gene-knockout Escherichia coli Based on the Inverse Flux Analysis with Experimental Verification

Md. Aminul Hoque1, Khandaker Al Zaid Siddiquee2, Kazuyuki Shimizu, Institute for Advanced Bioscience, Keio University, Tsuruoka, 997-0035, Japan; 2, Department of Biochemical Engineering and Science, Kyushu Institute of Technology,

Inverse Flux Analysis (IFA) was utilized to investigate the effect of gene-knockout on the metabolic flux distribution of Escherichia coli. In particular, it was shown from IFA that @if pyk was knocked-out, then the flux through ppc and TCA cycle pathway increased, while the acetate production flux reduced. To verify this IFA result, we cultivated pykF- E.coli and compared the fermentation data of E.coli K12. The enzyme activities of G6PDH, 6PGDH, Pgi, Pfk, Pyk, Mez, MDH, Ppc, and Pyk were also measured. Those data well coincided with the IFA result. In the case when ppc was knocked out, IFA implied the increase in acetate production as compared with that of the wild type. However, the experimental result shows the reversed phenomenon, where it was found that when ppc was knocked out, another anaplerotic pathway such as glyoxylate pathway was activated. From the present research, it was be shown that the theoretical approach using computer shows some powers but needs careful attention.